How can I edit the email subject and body?

You can edit the email content of the notifications to suit your business theme. Remember, only the content of enabled email notifications can be edited so if you want to edit the content of a disabled notification you have to enable it first.

To edit the content,

In the Email Notifications sections, click the button Default next to template you want to edit.

In the following pop-up, edit the email content and click on Save.

Note:

You can also use the Insert Placeholders drop-down button at the top-right to insert placeholders into your email content. Know more about Placeholders.

You can use the Save as New button at the bottom (next to Save) to save it as a new email template. This can be useful to associate a specific template to a specific product.